<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Model;
use DB;

class Threed extends Model
{
    protected $guarded = ['id']; 

    public function dong()
    {
    	return $this->belongsTo(Threed::class,'next1','id');
    }
    public function nan()
    {
    	return $this->belongsTo(Threed::class,'next2','id');
    }
    public function xi()
    {
    	return $this->belongsTo(Threed::class,'next3','id');
    }
    public function bei()
    {
    	return $this->belongsTo(Threed::class,'next4','id');
    }

    



    
}
